Rotary pump



Oct. 16, 1962 A. c. MAMO ETAL ROTARY PUMP Filed March 27, 1961fnv/enfans.' grazia@ CMczmn d ZesZczw fzEragewS/i United States Patent O3,058,427 RGTARY PUMP Anthony C. Mama, Des Plaines, and BoleslawPietraszewski, Chicago, lll., assignors to Borg-Warner Corporation,Chicago, Ill., a corporation of Illinois Filed Mar. 27, 1961, Ser. No.98,483 6 Claims. (Cl. 1433-136) .This invention relates to apositive-displacement hydraulic pump and more particularly to a pump ofthis type comprising a cylindrical casing having a cylindrical rotormounted eccentrically therein which is provided with but one vane havinga sealing roller at the end thereof.

It is an important object of this invention to provide an improved pumpof this type wherein the rotor is provided with an intake cavity on oneside thereof and an outlet cavity on the other side thereof.

It is another object of this invention to provide a rotor having onevane with a roller at the end thereof in sealing engagement with theinner periphery of the casing and another roller in the casing extendingthrough the inner periphery thereof in sealing engagement with therotor.

It is also an object of this invention to provide a pump of this typewhich is economical to manufacture.

This invention consists of the novel constructions, arrangements anddevices to be hereinafter described and claimed for carrying out theabove stated objects and such other objects as will appear from thefollowing description of a preferred form of the invention, illustratedwith reference to the accompanying drawings, wherein:

FIG. 1 is a cross sectional view taken on line 1--1 of FIG. 2 of a pumpconstructed according to this invention;

FIG. 2 is a view taken on line 2-2 in the direction as shown in FIG. l;and

FIG. 3 is a view taken on line 3-3 in the direction as shown in FIG. l.

Like characters of reference designate like parts in the several views.

Referring now to FIG. l, a cylindrical casing is shown, which comprisesa main portion 11 and a cover plate 12. The main portion 11 has aperipheral wall 13. Bolts 14 are provided for attaching the cover plate12 to the main portion 11 thereby providing a cylindrical cavity 15within the cylindrical casing 1i?. A cylindrical rotor 16 is positionedwithin the cylindrical cavity 15 and is of a width to provide adequatetolerance for rotative movement between side walls 17 and 18 of thecavity 15 and yet of adequate width to minimize fluid loss. Thecylindrical rotor 16 has a Vmedial wall 19 thereby providing a suctioninlet cavity 2@ on one side thereof and a pressure outlet cavity 21 onthe other side thereof which are of appreciable volumetric capacity. Thewall 19 has a thickened wall portion 22 of a width equal to that of therotor 16 and extends outwardly to the perimeter 23 of the rotor 16 andinwardly beyond the center thereof. The thickened wall portion 22 isprovided with a rectangular recess 24 extending radially from a pointshort of the center of the rotor 16 and through its outer perimeter 23.A vane 25 is slideably mounted within the recess 23 and carries a roller26 of a length equal to the width of the rotor 16, within a cylindricalbore 27 which passes through the outer end of the arm 25 and at a rightangle with respect to the rotor 16. The location of the bore 27 is suchthat it cuts through an outer end face 28 of the arm 25 therebypermitting the roller 26 to protrude therethrough. A spring 29 is biasedbetween the arm 25 and an inner wall 3i) of the recess 24.

The rotor 16 is provided with a bore 31 extending concentricallytherethrough in coaxial alignment with a 3,58AZ7 Patented Ojct. 16, 1962ICC pair of bores 32 and 33 extending through the casing 10. The bores32 and 33 are eccentrically positioned with respect to the cylindricalcavity 15. A shaft 34 is keyed within the bore 31 by a key 35 andjournaled within the pair of bores 31 and 32 whereby the rotor 16 ismounted eccentrically within the cavity 15.

The peripheral wall 13 is provided with a bore 36 extending at rightangles through a face 37 of the peripheral wall 13 and of a depth lessthan the width of the cylindrical cavity 15 and positioned medially withrespect thereto. The location of the bore 36 is such that it cutsthrough an inner peripheral face 33 of the peripheral wall 13 therebyproviding an opening 39 in communication with the cylindrical cavity 15and a pair of lands 40 and '41 on opposite sides of the opening 39whereby the roller 26 may ride on the lands 411 and 41 as it movesacross the opening 39. A space 42 is provided in the bore 36 oppositethe opening 39 thereby providing an area for the insertion of a flatspring 43 for urging a sealing roller 44, carried in the bore 36, intosealing engagement with the outer periphery 45 of the rotor 16.

The casing 10 is also provided with a small bore 46 extending throughthe inner peripheral face 38 into communication with the bore 36 therebyproviding admission of hydraulic lluid into the bore 36 which providespressure as an additional means for urging the sealing roller 44inwardly.

The side Wall 17 has a suction intake port 47 therethrough incommunication with the suction inlet cavity 20 and the side wall 1S hasa pressure outlet port '48 in communication with the pressure outletcavity 21. The suction inlet cavity 20 is provided with an outlet port49 in communication with a iluid working space 50 which comprises thespace between the outer periphery 45 of the rotor 16 and the innerperipheral `face 38 of the peripheral wall 13. The pressure outletcavity 21 is provided with an inlet port 51 which is also incommunication with the iluid working space 50.

In operation, when the system is lled with uid and the vane 25 isretracted at the bottom or radial innermost position of its stroke, thesuction intake port 47 and the pressure outlet port 48 are momentarilyclosed by the thickened wall portion 22 which has a greater axial widththan the diameters of ports 47 and 4S. As the vane 25 moves slightlybeyond this point in a clockwise direction, both ports 47 and 48 beginto open and the fluid in the lluid working space 56 is driven ahead ofthe vane through the inlet port 51 into the pressure outlet cavity 21and thence through the pressure outlet port 48 as indicated by thearrows 52 in FIG. 2 and at the same time hydraulic uid is being suckedinto the Huid working space 56 by way of suction intake port 47, suctioninlet cavity 20 and outlet port 49 as indicated by arrows 53 as shown inFIG. 3.

It will be apparent that when the pump is in operation, the suctioninlet cavity 20 and the pressure outlet cavity 21 are always lled withfluid, as also is the fluid working space 50. Fluid loss is kept to aminimum by providing close tolerances between the sides of thecylindrical rotor 16 including the sides of the vane 25 and the sideWalls 17 and 18 of the cavity 15. Effective sealing against iluid lossbetween the end of the vane 25 and the inner peripheral face 38 of theperipheral wall 13 is provided by the roller 26 biased thereagainst bythe spring 29, and the sealing roller 44 being biased against the outerperiphery 45 of the rotor 16, is eective in sealing against iluid lossbetween the outer periphery 45 of the rotor 16 and the inner peripheralface 38 ofthe peripheral wall 13.

It is apparent from the above description of the operation of the pump,according to this invention, and the drawings that when the vane 25 isat the bottom of its stroke, the iiuid working space 50 is completelyfilled and as the vane 25 is moved in a clockwise direction by therotation of the rotor 16, all the fluid from the fluid working space 50is removed when the vane 25 again arrives at the bottom of its strokeand that in the meantimethe iuid working space 50 has again been iilledwhereby with each revolution a full charge of fluid is delivered by thepump.

We wish it to be understood that our invention is not to be limited tothe specific constructions and arrangements shown and described exceptonly insofar as the appended claims may be so limited, as it will beapparent to those skilled in the art that changes may be made withoutdeparting from the principles of the invention.

We claim:

l. A rotary pump comprising a casing having a peripheral wall and firstand second side walls thereby providing a cylindrical cavity therein, acylindrical rotor having rst and second sides mounted eccentricallywithin said cylindrical cavity by means of a shaft iXed concentricallyin said rotor and journaled in the said side Walls of the said casingthereby providing a fluid working space between the outer periphery ofthe said rotor and the inner periphery of said peripheral wall, saidrotor having a iirst cavity in said first side thereof and a secondcavity in said second side thereof, an intake port in said iirst sidewall in communication with said first cavity, an outlet port in saidsecond side wall in communication with said second cavity, a rst port insaid rst cavity in communication with said fluid working space, a secondport in said second cavity in communication with said fluid workingspace, said rotor having a radial recess, a vane dening means slideablymounted in said rotor recess, and a spring interposed between said rotorand said vane, urging said vane radially outwardly.

2. A rotary pump according to claim 1 wherein the said vane carries asealing roller in a bore that cuts through the end of the said vane atits most radially outward end whereby the said roller contacts the saidinnerperiphery of said peripheral wall in sealing engagement.

3. A rotary pump according to claim l wherein said rotor is providedWith a medial wall between said first and second cavities said medialwall having a thickened portion extending from the said outer peripheryof Vsaid rotor and radially inwardly beyond the center thereof and of awidth equal to the width of said rotor, said thickened portion having arecess, the saidvane being slideably mounted therein, said vane having awidth equal to the width of said rotor and the said thickenedportionbeing of a width greater than the diameters of the said inlet and outletports,

4. A rotary pump comprising a casing having a peripheral wall and iirstand second side walls thereby providing a cylindrical cavity therein,said peripheral wall having a bore laterally therethrough which cutsthrough the inner periphery of said peripheral wall thereby providing anopening in communication with said cylindrical cavity, a sealing rollerin said bore, a spring interposed between said sealing roller and saidperipheral wall, a cylindrical rotor mounted eccentrically within saidcylindrical cavity bymeans of a.v shaft tixed concentrically in saidrotor and journaled in the said side walls of said casing therebyproviding a huid working space between the outer periphery of the saidrotor and the inner periphery of said peripheral wall said rotor havinga iirst cavity in said first side thereof and a second cavity in saidsecond side thereof, an intake port in said iirst side wall incommunication with said iirst cavity, an outlet port in said second sidewall in communication with said second cavity, a iirst port in saidfirst cavity in communication with said uid working space, a second portin said second cavity in communication with said Huid working space,said rotor hav-ing a radial recess, a vane slideably mounted in saidrotor recess, and a spring interposed between said vane and said rotorurging said vane outwardly.

5. A rotary pump according to claim 4 wherein the said bore is of adepth less than the Width of the said cylindrical cavity and positionedmedially with respect thereto the said cylindrical cavity therebyproviding a pair of lands atv each end of the said opening.

6. A rotary pump according to claim 4 including a second bore adjacentthe said bore and extending through the said inner periphery of saidperipheral Wall in communication with said bore.

References Cited in the tile of this patent UNTED STATES PATENTS 234,957Chamberlin Nov. 30, 1880 674,837 Gadberry May 21, 1901 727,749 Cook May12, 1903 749,712 Allen Jan. 19, 1904 865,117 Muhl Sept. 3, 19071,359,792 Cracknell Nov. 23, 1920 2,818,025 Hein Dec. 31, 1957 FOREIGNPATENTS 227,885 Great Britain Jan. 26, 1925 421,374 Germany Nov. 11,1925 523,391 France Apr. 21, 1921

